Another potentially interesting article in the same “ahead of print” issue is “Microbial community dynamics of an urban drinking water distribution system subjected to phases of chloramination and chlorination treatments” by Hwang et al (including Gary Andersen Lawrence Berkeley Lab and the Sloan Foundation funded BIMERC group at UC Berkeley and LBL).

They reported: “Microbial community analysis revealed that among major core populations, Cyanobacteria, Methylobacteriaceae, Sphingomondaceae, and Xanthomonadaceae were more abundant in chlorinated water, and Methylophilaceae, Methylococcaceae, and Pseudomonadaceae in chloraminated water.” Also, “Overall, reversible shifts in microbial communities were especially pronounced with chloramination, suggesting stronger selection of microbial populations from chloramines than chlorine.”